Cardiac Shunt Device and Delivery System

ABSTRACT

A shunt device for creating a shunt in an atrial septum includes magnets coupled to inner loops of a coil comprising at least two inner loops and two outer loops, with a diameter of each of the inner loops being less than a diameter of the outer loops. The coil is made of a shape memory alloy (SMA) and is adapted to exert a compressive force upon layers of tissue caught between the inner loops of the coil. The magnets are adapted to provide additional compressive force to adjacent inner loops of the coil, thereby further causing the coil to cut through the layers of tissue and create a shunt. The diameter of the resultant shunt is less than the diameter of the outer loops, thereby preventing the outer two loops from passing through the created shunt. At least one end of the coil has a connection means for connecting with a delivery device.

CROSS-REFERENCE

The present application is a continuation application of U.S. patentapplication Ser. No. 16/737,790, entitled “Cardiac Shunt Device andDelivery System” and filed on Jan. 8, 2020, which is a divisionapplication of U.S. patent application Ser. No. 15/868,126, of the sametitle, filed on Jan. 11, 2018, and issued as U.S. Pat. No. 10,561,423 onFeb. 18, 2020, which relies on U.S. Provisional Patent Application No.62/444,995, entitled “Cardiac Anastomosis Device and Delivery System”and filed on Jan. 11, 2017, for priority. U.S. patent application Ser.No. 15/868,126 is also a continuation in part application of U.S. patentapplication Ser. No. 15/605,286, entitled “Magnetic Anastomosis Deviceand Delivery System”, filed on May 25, 2017, and issued as U.S. Pat. No.10,154,844 on Dec. 18, 2018, which, in turn, relies on, for priority,U.S. Provisional Application No. 62/425,951, entitled “AnastomosisDevice and Delivery System” and filed on Nov. 23, 2016, U.S. PatentProvisional Application No. 62/408,795, entitled “Anastomosis Device andDelivery System” and filed on Oct. 16, 2016, and U.S. Patent ProvisionalApplication No. 62/366,185, entitled “Anastomosis Device and DeliverySystem” and filed on Jul. 25, 2016. All of the above applications areherein incorporated by reference in their entirety.

FIELD

The present specification is directed toward formation of shunts inhuman bodies and, more specifically, to a device which uses magneticcompression to create a shunt in a human body and a delivery system fordeploying the device at a desired location within the body. The presentspecification is also directed toward controlling the flow of bodilyfluids through a body valve and, more specifically, toward using magnetsto control the flow through said valve.

BACKGROUND

In cases of heart disease, such as one which requires decompression ofone of the chambers of the heart, e.g. the left atrium or right atrium,a septal defect or shunt is created in the septum/wall between the twoheart chambers to allow for the flow of blood from the high-pressurechamber to the low-pressure chamber, thus decompressing the highpressure chamber. Most of these procedures are performed surgically orby using non-removable metal stent-like devices.

Prior art devices for creating shunts often comprise a piercing tipwhich can be hazardous and cause injury to adjacent organs.Additionally, most of the prior art techniques create the shuntinstantaneously, causing sudden increase in pressure and work-load on aportion of the heart which could result in acute heart failure. Also,most prior art devices are permanently implanted, creating the need forlong-term antiplatelet and anti-coagulant medication to prevent clotformation. These medications increase the risk of life-threateningconditions such as bleeding or stroke.

Hence, what is needed is an efficient and small shunt device which maybe delivered with ease within a human body for slowly creating a shuntover a period of time, resulting in a slow decompression of thehigh-pressure system and in turn, a slow increase in pressure andwork-load in the low-pressure system. What is also needed is a shuntdevice which can be removed safely after the shunt is formed, obviatingthe need for long-term anticoagulant or antiplatelet medications.Further, there is need for a shunt device which exerts a sufficientlyhigh compressive force on an organ wall to create a shunt, yet retains asmall enough profile to be delivered through a minimally invasivedelivery device, such as a catheter. There is also a need for a shuntdevice that does not rely solely on magnetic forces for correctorientation and positioning inside the human body.

Prior art devices for controlling valve function, specificallypreventing the back-flow or leakage of fluid, create a fixed restrictionwhich impedes the forward flow as well as restricting the backward flow,thereby increasing the pressure on the heart, and in turn, increasingthe work-load.

Hence, what is also needed is an efficient and small device which may bedelivered with ease within a human body and which dynamically controlsthe flow of fluid across a valvular structure. What is also needed is adevice that controls the flow of fluid in one direction preferentiallyover the opposite direction, thereby augmenting or restoring the normalvalvular function of a valve. What is also needed is a valve controldevice which can be removed safely.

SUMMARY

The present specification discloses a shunt device for creating a shuntin an atrial septum of a patient, comprising: a wire comprised of ashape memory alloy, wherein the wire is adapted to transform from asubstantially straight wire to a coil shape upon heating and wherein thewire, upon transforming to the coil shape, comprises at least two innerloops and at least two outer loops, wherein a diameter of the at leasttwo inner loops are each less than a diameter of each of the at leasttwo outer loops, and wherein the wire, when in the coil shape, isadapted to exert a compressive force upon layers of tissue caughtbetween the at least two inner loops; and a plurality of magnets coupledto the at least two inner loops, wherein the plurality of magnets areadapted to provide a compressive force to adjacent inner loops of thewire in the coil shape, thereby further causing the wire to cut throughthe layers of tissue and create a shunt of a diameter less than thediameter of the outer loops such that the at least two outer loops donot pass through said shunt.

Optionally, at least one end of the wire comprises a connection meansfor connecting with a delivery device. The connection means may comprisea nut and a screw.

Optionally, a diameter of the wire when in a coil shape ranges between0.1 mm to 10 mm and a length of the wire ranges from 1 cm to 250 cm.

Optionally, the wire comprises Nitinol.

Optionally, the plurality of magnets are positioned on the at least twoinner loops such that repulsive forces between adjacent magnets of theplurality of magnets on a same one of the at least two inner loops causesaid adjacent magnets to maintain a predefined distance between them.

Optionally, the plurality of magnets are rare earth magnets covered withat least one of gold, nickel or titanium.

Optionally, the wire, when in a coiled shape, has a maximum crosssectional diameter ranging from 5 mm to 50 mm.

Optionally, each of the plurality of magnets has a maximum crosssectional length ranging from 0.2 mm to 7 mm and a pull force rangingfrom 0.1 lb. to 4 lb.

Optionally, a pull force between any two consecutively placed magnets ofthe plurality of magnets is approximately 2.318 N.

Optionally, a length, an inner diameter and an outer diameter of each ofthe plurality of magnets is 3 mm, 0.66 mm and 2.5 mm respectively.

A shape of the shunt formed by using the shunt device may be determinedby a shape of the at least two inner loops.

Optionally, at least 50% of the adjacent magnets on each loop arearranged with like poles facing each other.

Optionally, adjacent magnets on each of the at least two inner loops areseparated by a non-ferromagnetic spacer, thereby preventing adjacentmagnets from attaching to each other.

Optionally, each of the at least two outer loops are connected toopposing ends of the at least two inner loops.

Optionally, two opposing tips of the wire correspond to ends of the atleast two outer loops and comprise a crimped probe at one of the twoopposing tips and a cautery probe at a second of the two opposing tips.The crimped probe may be attached to a screw as a connection means forconnecting the wire with a delivery device. A magnet of the plurality ofmagnets may at least partially encompass the cautery probe or the screw.The delivery device may comprise a mechanism for heating the shuntdevice prior to deploying in the body of the patient.

Optionally, each of the at least two outer loops is wave-shaped so thata location of each crest of one of the at least two outer loops isaligned with each trough of a second of the at least two outer loops.

Optionally, the shunt device further comprises a heat source adapted tobe connected to an end of the wire, wherein the heat source is adaptedto deliver energy to heat the wire and cause the wire to transform fromthe substantially straight wire to the coil shape.

The present specification also discloses a method for treating a valvedefect in a heart chamber of a patient's body, the method comprising:using a needle positioned in a catheter, piercing a portion of the heartchamber; delivering a wire proximate said portion of the heart chamber,wherein: the wire comprises a shape memory alloy; the wire is adapted totransform from a substantially straight wire to a coil shape uponheating; the wire, upon transforming to the coil shape, comprises atleast two inner loops and at least two outer loops; a diameter of atleast one of the at least two inner loops is less than a diameter of atleast one of the at least two outer loops; the wire, when in the coilshape, is adapted to exert a compressive force upon layers of tissuecaught between the at least two inner loops; and a plurality of magnetscoupled to the at least two inner loops, wherein the plurality ofmagnets are adapted to provide a compressive force to adjacent innerloops of the wire in the coil shape.

Optionally, the method further comprises delivering heat to the wire totransform the substantially straight wire to the coil shape using a heatsource adapted to be connected to an end of the wire.

The present specification also discloses a method for treating a valvedefect in a patient's body, the method comprising: delivering a deviceinto the patient's body, wherein the device comprises a wire made of ashape memory alloy, wherein the wire has a first part, comprising afirst end, and a second part, comprising a second end, wherein a firstmagnet is attached to the first part and wherein a second magnet isattached to the second part; using the first end, piercing a firstleaflet of the valve in order to create contact between the first magnetand the first leaflet; and using the first end, piercing a secondleaflet of the valve in order to create contact between the secondmagnet and the second leaflet, the attractive forces between the firstand the second magnets causing improved closure of the valve forpreventing or reducing back flow through the valve.

Optionally, the method further comprises delivering heat to the wire totransform the substantially straight wire to the coil shape using a heatsource adapted to be connected to an end of the wire.

The present specification also discloses a shunt device for treating avalve defect in a patient's body, the device comprising: a first magnetcoupled with a first shape memory alloy (SMA) wire adapted to changeshape from a predominantly linear wire into a coil when deployed withinthe body; and a second magnet coupled with a second shape memory alloy(SMA) wire adapted to change shape from a predominantly linear wire intoa coil when deployed within the body; the first wire piercing a firstleaflet of the valve for attaching the first magnet with the firstleaflet, the second wire piercing a second leaflet of the valve forattaching the second magnet with the second leaflet, the attractiveforces between the first and the second magnets causing improved closureof the valve for preventing or reducing back flow through the valve.

Optionally, the shunt device further comprises means of coupling with adelivery device for deploying the device for treating a valve defect ata predefined site within a body, the delivery device comprising: adelivery catheter for pushing the device in through an insertion tube ofa catheter and out at the site through a tip of an catheter, wherein thedelivery catheter comprises a threaded distal end for coupling with thedevice for treating a valve defect and wherein the catheter is adaptedto be rotated to release said device at the deployment site. Optionally,the delivery device further comprises a non-cautery needle adapted topierce a tissue for deploying the device for treating a valve defecttherein. Optionally, the delivery device further comprises a mechanismfor heating the first and the second SMA wires prior to deploying in thepatient's body.

The present specification also discloses shunt devices for creating ashunt in an atrial septum, comprising a plurality of magnets coupled toat least two inner loops of a coil comprising at least two inner loopsand two outer loops, a diameter of each of the inner loops being lessthan a diameter of the outer loops, said coil being comprised of a shapememory alloy (SMA), wherein the coil is adapted to exert a compressiveforce upon layers of tissue caught between the inner loops of the coil,and wherein the plurality of magnets are adapted to provide acompressive force to adjacent inner loops of the coil, thereby furthercausing the coil to cut through the layers of tissue and create a shuntof a diameter less than the diameter of the outer loops, therebypreventing the outer two loops from passing through the created shunt,wherein at least one end of the coil comprises a connection means forconnecting with a delivery device.

The connection means may be one of a nut and a screw.

Optionally, a diameter of the coil ranges between 0.1 mm to 10 mm and alength of the coil ranges from 1 cm to 250 cm.

The SMA coil may be a Nitinol coil.

Optionally, the magnets are positioned such that repulsive forcesbetween adjacent magnets on the same coil cause said adjacent magnets tomaintain a predefined distance between said adjacent magnets.

Optionally, the magnets are rare earth magnets covered with at least oneof gold, nickel and titanium.

Optionally, when in a coiled state, a maximum cross sectional diameterof the SMA coil ranges from 5 mm to 50 mm.

Each of the magnets may have a maximum cross sectional length rangingfrom 0.2 mm to 7 mm and a pull force ranging from 0.1 lb. to 4 lb.

Optionally, a pull force between any two of the consecutively placedmagnets on the coil is approximately 2.318 N.

Optionally, a length, inner diameter and outer diameter of each of themagnets is 3 mm, 0.66 mm and 2.5 mm respectively.

A shape of the shunt formed by using the SMA coil and magnets may bedetermined by the shape of the coiled SMA coil.

Optionally, at least 50% of the adjacent magnets on each loop of thecoil are arranged with like poles facing each other, thereby creating arepulsive force between two adjacent magnets in a single inner loop ofthe coil.

Optionally, two adjacent magnets on a single inner loop of the coil areseparated by a non-ferromagnetic spacer, thereby preventing the twoadjacent magnets from attaching to each other.

The present specification also discloses a delivery device for deployinga cardiac shunt device at a predefined site within a body, the shuntdevice comprising a plurality of magnets coupled to at least two innerloops of a coil comprising at least two inner loops and two outer loops,a diameter of each of the inner loops being less than a diameter of theouter loops, the delivery device comprising: a delivery catheter forpushing the device in through an insertion tube of a catheter and out atthe site through a tip of an catheter, wherein the delivery cathetercomprises a threaded distal end for coupling with the shunt device andwherein the catheter is adapted to be rotated to release the shuntdevice at the deployment site.

Optionally, the delivery device further comprises a non-cautery needleadapted to pierce a tissue for deploying the shunt device therein.

Optionally, the delivery device further comprises a mechanism forheating the SMA coil prior to deploying the shunt device, thereinassisting in shape transformation of the device from a pre-deploymentconfiguration to a post-deployment configuration.

The present specification also discloses a device for treating a valvedefect comprising a first magnet coupled with a first shape memory alloy(SMA) wire adapted to change shape from a non-coiled wire into a coilwhen deployed within a body, and a second magnet coupled with a secondshape memory alloy (SMA) wire adapted to change shape from a non-coiledwire into a coil when deployed within a body, the first wire piercing afirst leaflet of a valve for attaching the first magnet with theleaflet, the second wire piercing a second leaflet of the valve forattaching the second magnet with the second leaflet, the attractiveforces between the first and the second magnets aiding complete closureof the valve and preventing or restricting back flow. While duringforward flow, the pressure from flow on the leaflets separates themagnets and, as the distance between magnets increases, the attractionforce decreases. Therefore, the valve defect device does not produce anysignificant impairment of valvular function during forward flow.

The present specification also discloses a delivery device for deployinga device for treating a valve defect at a predefined site within a body,the delivery device comprising: a delivery catheter for pushing thedevice in through an insertion tube of a catheter and out at the sitethrough a tip of the catheter, wherein the delivery catheter comprises athreaded distal end for coupling with the device for treating a valvedefect and wherein the catheter is adapted to be rotated to release saiddevice at the deployment site.

Optionally, the delivery device further comprises a non-cautery needleadapted to pierce a tissue for deploying the valve defect devicetherein.

Optionally, the SMA wires in the device is adapted to make the puncture.

Optionally, the delivery device further comprises a mechanism forheating the SMA coil prior to deploying the valve defect device, thereinassisting in shape transformation of the device from a pre-deploymentconfiguration to a post-deployment configuration.

The aforementioned and other embodiments of the present shall bedescribed in greater depth in the drawings and detailed descriptionprovided below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will befurther appreciated, as they become better understood by reference tothe detailed description when considered in connection with theaccompanying drawings:

FIG. 1 illustrates a straight shape memory alloy (SMA) wire which coilswithin a human body, in accordance with an embodiment of the presentspecification;

FIG. 2 illustrates a plurality of magnets threaded on loops of an SMAwire, in accordance with an embodiment of the present specification;

FIG. 3A illustrates a coiled shunt wire, in accordance with anembodiment of the present specification;

FIG. 3B illustrates a plurality of magnets and spacers threaded on innerloops of the coiled shunt wire shown in FIG. 3A;

FIG. 3C illustrates a diagrammatic view of a plurality of magnets andspacers threaded on inner loops of the coiled shunt wire shown in FIG.3A;

FIG. 4 illustrates a human heart with a coiled SMA wire creating aseptum defect, in accordance with an embodiment of the presentspecification;

FIG. 5A illustrates a diagrammatical representation of an SMA coil forcreating a septal defect, in accordance with an embodiment of thepresent specification;

FIG. 5B is another view of the SMA coil for creating a septal defectshown in FIG. 5A;

FIG. 5C illustrates a cross sectional view of the SMA coil for creatinga septal defect shown in FIG. 5A;

FIG. 6A illustrates a catheter carrying a needle being deployed in ahuman heart for creating a puncture in a wall between the left and rightatriums of the heart, in accordance with an embodiment of the presentspecification;

FIG. 6B illustrates an SMA coil comprising magnets deployed within theleft and right atriums through the puncture created in the wall forcausing a septal defect in the wall, in accordance with an embodiment ofthe present specification;

FIG. 7 is a flowchart illustrating the steps of using a coiled SMA wirefor creating a septal defect in a human heart, in accordance with anembodiment of the present specification;

FIG. 8A illustrates a human heart comprising a mitral valve;

FIG. 8B illustrates a human heart suffering from a mitral valve prolapsecondition;

FIG. 9A illustrates a closed mitral valve in a human heart;

FIG. 9B illustrates a mitral valve in prolapse condition;

FIG. 9C illustrates a pair of magnets deployed on each leaflet of theprolapsed mitral valve shown in FIG. 9B, in accordance with anembodiment of the present specification;

FIG. 9D illustrates the prolapsed mitral valve of FIG. 9C closed due toattractive forces between the magnets, in accordance with an embodimentof the present specification;

FIG. 10A illustrates a magnet being delivered to a mitral valve leaflet,in accordance with an embodiment of the present specification;

FIG. 10B illustrates leaflets of the mitral valve closed due toattraction between the magnets, in accordance with an embodiment of thepresent specification;

FIG. 10C illustrates an SMA wire coupled with a magnet, in accordancewith an embodiment of the present specification;

FIG. 10D illustrates a non-linear configuration of a SMA wire, uponbeing delivered at a deployment site, in accordance with an embodimentof the present specification;

FIG. 10E illustrates another non-linear configuration of a SMA wire,upon being delivered at a deployment site, in accordance with anembodiment of the present specification;

FIG. 10F illustrates another non-linear configuration of a SMA wire,upon being delivered at a deployment site, in accordance with anembodiment of the present specification;

FIG. 11A illustrates a plurality of heart valves closed by using magnetsthreaded in SMA wires, in accordance with an embodiment of the presentspecification;

FIG. 11B illustrates a magnet threaded in an SMA wire deployed at avalve site, in accordance with an embodiment of the presentspecification;

FIG. 12 illustrates a graph showing the exponential relationship betweenthe distance and magnetic force between magnets, in accordance with anembodiment of the present specification;

FIG. 13 illustrates a magnet threaded on an SMA wire to be deployedwithin a body via a push catheter, in accordance with an embodiment ofthe present specification;

FIG. 14A illustrates a side view of a device for creating a septaldefect and comprising an SMA wire with a plurality of magnets, inaccordance with an embodiment of the present specification;

FIG. 14B illustrates a cross sectional view of the device for creating aseptal defect of FIG. 14A;

FIG. 14C illustrates a top-down view of the device for creating a septaldefect of FIG. 14A;

FIG. 14D illustrates a perspective view of the device for creating aseptal defect of FIG. 14A;

FIG. 15A illustrates a side view of a device for creating a septaldefect and comprising two SMA wires with a plurality of magnets, inaccordance with an embodiment of the present specification;

FIG. 15B illustrates a cross sectional view of the device for creating aseptal defect of FIG. 15A;

FIG. 15C illustrates a top-down view of the device for creating a septaldefect of FIG. 15A;

FIG. 15D illustrates a perspective view of the device for creating aseptal defect of FIG. 15A;

FIG. 16A illustrates a top-down view of a device for creating a septaldefect and comprising an SMA wire with a plurality of magnets andcautery probes, in accordance with an embodiment of the presentspecification; and

FIG. 16B illustrates a perspective view of the device for creating aseptal defect of FIG. 16A.

DETAILED DESCRIPTION

In various embodiments, a shape memory alloy (SMA) or smart alloy wireis used to create a shunt. A desired shape and size of the shunt iscreated by cutting through tissue layers in a human body to create theopening for the shunt. In an embodiment, a straight piece of an SMAwire, or a longitudinally stretched coil, or any other substantiallyplanar structure, is delivered at a location requiring a shunt within abody. In an embodiment, the SMA wire is either superelastic or heatsensitive and curls up into a spring like coil in response to body heatwithin the body. In various embodiments, the wire has a straight or alongitudinally stretched coil or an elongate shape at room temperatureand a compressed coil shape at the human body temperature, which is inthe preferred range of 97.7 degrees Fahrenheit (F) to 99.5 degrees F.The coil may take a compressed shape at any temperature greater than 96degrees F.

In another embodiment, a coiled Nitinol wire having at least two innerloops and at least two outer loops, wherein the diameter of the innerloops is less than the diameter of the outer loops, is used to create aseptal defect or shunt between two chambers of a human heart. The innerloops of the wire are threaded with magnets to increase the compressiveforce between the coil loops creating the shunt, while the outer loopsare used to anchor the coil in a desired position and preventdislodgement at any time during or after the shunt formation.

The compressed coil defines the desired shape and dimensions of thedesired shunt. The compressing coil produces a compression force ontissue caught between loops of the coil. The coiling action also causesthe wire to create ischemia, pressure necrosis and cut through thedesired tissue layers, creating a shunt between two adjacent bodytissues. In an embodiment, a plurality of magnets is provided on atleast two loops of the coiled wire. Magnets provided on adjacent ringsattract each other, thereby enhancing the cutting action of the coil. Insome embodiments, compression force is provided by the combination ofthe coiling wire and attraction force between the magnets. In someembodiments, the shape of the resultant shunt is predominantlydetermined by the shape of the coil and not by the forces between themagnets. In various embodiments, the number of magnets used and thelength of the magnets are determined by the shape, dimensions or timeneeded to form a shunt.

The term “and/or” means one or all of the listed elements or acombination of any two or more of the listed elements.

The terms “comprises” and variations thereof do not have a limitingmeaning where these terms appear in the description and claims. In thedescription and claims of the application, each of the words “comprise”“include” and “have”, and forms thereof, are not necessarily limited tomembers in a list with which the words may be associated.

Unless otherwise specified, “a,” “an,” “the,” “one or more,” and “atleast one” are used interchangeably and mean one or more than one.

For any method disclosed herein that includes discrete steps, the stepsmay be conducted in any feasible order. And, as appropriate, anycombination of two or more steps may be conducted simultaneously.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc.). Unless otherwise indicated, all numbersexpressing quantities of components, molecular weights, and so forthused in the specification and claims are to be understood as beingmodified in all instances by the term “about.” Accordingly, unlessotherwise indicated to the contrary, the numerical parameters set forthin the specification and claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, and not as an attempt to limit thedoctrine of equivalents to the scope of the claims, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. All numerical values, however, inherently contain a rangenecessarily resulting from the standard deviation found in theirrespective testing measurements.

The present specification is directed towards multiple embodiments. Thefollowing disclosure is provided in order to enable a person havingordinary skill in the art to practice the invention. Language used inthis specification should not be interpreted as a general disavowal ofany one specific embodiment or used to limit the claims beyond themeaning of the terms used therein. The general principles defined hereinmay be applied to other embodiments and applications without departingfrom the spirit and scope of the invention. Also, the terminology andphraseology used is for the purpose of describing exemplary embodimentsand should not be considered limiting. Thus, the present invention is tobe accorded the widest scope encompassing numerous alternatives,modifications and equivalents consistent with the principles andfeatures disclosed. For purpose of clarity, details relating totechnical material that is known in the technical fields related to theinvention have not been described in detail so as not to unnecessarilyobscure the present invention.

It should be noted herein that any feature or component described inassociation with a specific embodiment may be used and implemented withany other embodiment unless clearly indicated otherwise.

FIG. 1 illustrates a straight SMA wire 102 which coils up within a humanbody, in accordance with an embodiment of the present specification.Wire 102 is made of an SMA material such as Nitinol (NiTi). Ashape-memory alloy (SMA, smart metal, memory metal, memory alloy, musclewire, smart alloy) is an alloy that “remembers” its original shape andthat when deformed returns to its pre-deformed shape when heated. NiTialloys change from martensite to austenite upon heating. In anembodiment, the SMA wire 102 is made of a copper-aluminum-nickel alloy.In another embodiment the SMA wire 102 is made of a nickel-titaniumalloy. In an embodiment, a diameter of the wire 102 ranges between 0.1to 6 mm and the wire 102 has a maximum strain of less than 10% in anuncoiled position and a maximum cross sectional dimension ranging from 5mm to 50 mm. In various embodiments, for a 5% strain, and for wirediameters less than 0.75 mm, ranging between 0.75 mm and 1 mm, andgreater than 1 mm, the diameters of the coiled up wires are less than 15mm, between 15 mm and 20 mm, and greater than 20 mm respectively. In anembodiment, for a 10% strain, and for wire diameters of 1 mm, 1.25 mm,1.5 mm, 1.7 mm, 2 mm and 2.5 mm, the diameters of the coiled up wiresare 10 mm, 12.5 mm, 15 mm, 17 mm, 20 mm and 25 mm respectively. In anembodiment, for a 6% strain, and for wire diameters of 0.6 mm, 0.75 mm,0.9 mm, 1.02 mm, 1.2 mm and 1.5 mm, the diameters of the coiled up wiresare 5 mm, 10 mm, 12.5 mm, 15 mm, 17 mm, 20 mm and 25 mm respectively.Further, in various embodiments, the wire 102 coils up into at least 2loops upon delivery into a body.

A_(s) and A_(f) are the temperatures at which the transformation frommartensite to austenite starts and finishes. Upon insertion into a humanbody and placement at a shunt site, wire 102, depicting a pre-deploymentconfiguration, changes shape and coils up as coil 104 or 106, depictinga post-deployment configuration, in response to the higher temperatureof the human body relative to the room temperature. In embodiments, wire102 changes shape and coils up as 104 or 106 in response to an input ofenergy, such as electrical energy generating internal resistance andheat, into one end of the wire. It should be appreciated that whereverheat from the body is mentioned herein, such heat may be augmented bythe application of energy, such as electrical energy, to increase theamount of heat in the wire and to improve the transition to austenite.Such an application may occur by attaching the wire, at one end, to adetachable second wire, wherein the second wire is adapted to receive,and transmit, electrical or heat energy. In some embodiments, connectingcomponents 108 are provided at one or more ends of the wire 102 forattachment with a delivery catheter. In an embodiment, the deliverycatheter comprises a mechanism for heating the SMA wire 102 duringdeployment for assisting in shape transformation of the wire from thepre-deployment configuration to the post-deployment configuration. Invarious embodiments, the A_(f) temperature of the wire is less than orequal to 40° C. and A_(s) temperature of the wire is less than or equalto 37° C. In various embodiments, the strain on the Nitinol wire in itsmartensite shape is less than or equal to 10%. In one embodiment, thecoil has a circular cross-section with a radius r where thecircumference of the coil is 2πr and the area of the coil is πr² whereinthe coil creates a shunt opening of a radius approximately r and areaπr². In various embodiments, the diameter of the wire 102 ranges from0.1 mm to 10 mm and the length of the wire 102 ranges from 1 cm to 250cm.

FIG. 2 illustrates a plurality of magnets 202 a, 202 b, 202 c, 202 d,202 e, 202 f threaded on loops 204, 206 of an SMA wire, in accordancewith an embodiment of the present specification. Magnets 202 a, 202 b,202 c, 202 d, 202 e, 202 f are threaded on loops 204 and 206 of coil200. In an embodiment, coil 200 is a Nitinol wire that coils up inresponse to temperature change. A repulsive force acts between adjacentmagnets 202 a, 202 b and 202 c which are threaded on the same loop 204,thereby maintaining a desired distance between said magnets. Similarly,a repulsive force acts between adjacent magnets 202 d, 202 e and 202 fwhich are threaded on the same loop 206, thereby maintaining a desireddistance between these magnets. An attractive force acts between themagnets threaded on loop 204 and the magnets on loop 206. Hence, thereis attraction between the magnets 202 a and 202 d, between magnets 202 band 202 e, and between magnets 202 c and 202 f. The attraction betweenthe magnets on adjacent loops creates a compressive force 207 betweenloops of the coil, drawing the loops together to cut tissue between theloops and allow for shunt formation. In an embodiment, at least twomagnets are coupled with two adjacent loops of the coil 200 and the wirecoils up into at least two loops. In an embodiment, the magnets are rareearth magnets covered with a biocompatible material such as gold,nickel, Teflon, parylene, copper, zinc, silicone, epoxy or titanium. Inan embodiment, the coil 200 includes an RFID tag 210 to assist in thelocalization of the coil 200 after deployment and during shuntformation. Using an RFID scanner, the position of the coil can beidentified, through communications with the embedded RFID tag, todetermine the precise location of the coil in the patient without theneed for radiation for visualization.

In one embodiment, the Nitinol coil applies an amount of pressure lessthan or equal to 50 mm Hg on the tissue and the combined coil andmagnets apply an amount of pressure greater than 50 mm Hg on the tissue.In another embodiment, the Nitinol coil applies an amount of pressureless than or equal to 80 mm Hg on the tissue and the combined coil andmagnets apply an amount of pressure greater than 80 mm Hg on the tissue.In yet another embodiment, the Nitinol coil applies an amount ofpressure less than or equal to 120 mm Hg on the tissue and the combinedcoil and magnets apply an amount of pressure greater than 120 mm Hg onthe tissue. In yet another embodiment, the Nitinol coil applies anamount of pressure less than or equal to 150 mm Hg on the tissue and thecombined coil and magnets apply an amount of pressure greater than 150mm Hg on the tissue. In another embodiment, the Nitinol coil applies anamount of pressure less than or equal to 200 mm Hg on the tissue and thecombined coil and magnets apply an amount of pressure greater than 200mm Hg on the tissue. In an embodiment, the coil pressure at each coiltissue interface is sufficient to impede the capillary flow in thetissue by greater than 50%. In an embodiment, the coil creates apressure of more than or equal to 20 mm Hg at more than one fourth ofthe circumference of coil and the pressure is relatively equallydistributed among the two semicircles of each coil loop. In anembodiment, the pressure is more than or equal to 20 mm Hg at two ormore points that are on the opposite sides on each coil loop.

In some embodiments, the shunt device is connected to a delivery deviceby a nut and a screw. In other embodiments, the shunt device isconnected to a delivery device by a grasping mechanism. In embodiments,a diameter of the coil ranges between 0.1 mm to 10 mm and a length ofthe coil ranges from 1 cm to 250 cm. In various embodiments, when in acoiled state, a maximum cross sectional diameter of the SMA coil rangesfrom 5 mm to 50 mm. In embodiments, each of the magnets has a maximumcross sectional length ranging from 0.2 mm to 7 mm and a pull forceranging from 0.1 lb. to 4 lb. In embodiments, a pull force between anytwo of the consecutively placed magnets on the coil is approximately2.318 N. In some embodiments, a length, inner diameter and outerdiameter of each of the magnets is 3 mm, 0.66 mm and 2.5 mmrespectively. In embodiments, a shape of the shunt formed by using theSMA coil and magnets is determined by the shape of the coiled SMA coil.In some embodiments, at least 50% of the adjacent magnets on each loopof the coil are arranged with like poles facing each other, therebycreating a repulsive force between two adjacent magnets in a singleinner loop of the coil.

In some embodiments, the majority of the compressive force, as describedabove, is initially provided by the SMA coil. However, as the magnetsphysically converge closer together, the magnetic compressive forceovertakes the compressive force provided by the Nitinol coil and drivesthe shunt formation.

FIG. 3A illustrates a coiled shunt wire, in accordance with anembodiment of the present specification. Coil 302 comprises two innerloops 320 and two outer loops 322, wherein a diameter of the inner loops320 is less than a diameter of the outer loops 322 of coil 302. FIG. 3Billustrates a plurality of magnets 304 and spacers 306 threaded on innerloops 320 of the coiled shunt wire shown in FIG. 3A. FIG. 3C illustratesa diagrammatic view of a plurality of magnets 304 and spacers 306threaded on inner loops 320 of the coiled shunt wire shown in FIG. 3A.Referring to FIGS. 3A, 3B and 3C, the inner loops 320 of coil 302 arethreaded with two or more rows of magnets 304 and spacers 306, while twoor more outer loops 322 of coil 302 do not have magnets and spacersthreaded on them. The diameter of the inner loops 320 is less than thediameter of the outer loops 322 of coil 302. The compressive force ofthe magnets 304 creates a septal defect or shunt of a diameter less thanthe diameter of the outer loops 322, thereby preventing the outer twoloops 322 from passing through the septal defect, anchoring the coil 302to the septal defect and hence preventing its spontaneous passage aftera septal defect is formed.

In embodiments, spacers 306 are included on the coil 302 between eachpair of magnets 304 for decreasing the number of magnets required forachieving a required compressive force. In an embodiment, the spacers306 are composed of a non-ferromagnetic or biocompatible material. Invarious embodiments, the spacers 306 comprise silicone or Nitinol tubesor O-rings or circular balls. In an embodiment, an outer diameter of aspacer 306 ranges between 25% and 300% of the outer diameter of a magnet304 and a length of a spacer 306 is less than five times a length of amagnet 304.

FIG. 4 illustrates a human heart 400 with a coiled SMA wire 422 creatinga septal defect 424, in accordance with an embodiment of the presentspecification. Heart 400 comprises a right atrium 402, a right ventricle404, a left atrium 406, a left ventricle 408, a tricuspid valve 418, anda mitral valve 420. Also depicted in relation to the heart 400 are asuperior vena cava 410, an inferior vena cava 412, a main pulmonaryartery 414, and an aorta 416. In cases of heart disease, such as onewhich requires decompression of one of the chambers of the heart (e.g.the left atrium 406), a septal defect or shunt 424 is created by using acoiled SMA wire 422. The SMA coil 422, which, in an embodiment,comprises a Nitinol wire, is delivered through a hole punctured by acatheter or needle in the left atrium wall via an endoscope. In otherembodiments, the SMA wire 422 in the device is adapted to make thepuncture. In response to exposure to body heat, the Nitinol wire changesshape and coils up, holding the tissue of the left atrium 406 wall andthe right atrium 402 wall in between the turns of coil 422 as shown inFIG. 4, thereby forming a shunt 424 between the left atrium 406 and theright atrium 402 and decompressing the left atrium 406. In someembodiments, the device comprises a heat source adapted to be connectedto an end of the wire, wherein the heat source is adapted to deliverenergy to heat the wire and cause the wire to transform from thesubstantially straight wire to the coil shape. In an embodiment, magnetsmay be threaded on the coil 422 (such as shown in FIGS. 3B and 3C) tofurther increase the compressive force. In various embodiments, theshunt is formed over a period of time, allowing for neovascularizationof the shunt to occur, resulting in a robust and stable shunt. Creatingthe shunt over a period of time allows pressure in a high-pressuresystem (pressure is high in the left atrium) to be relieved more slowlythan in prior art approaches. Slowly relieving the pressure lessens theburden placed on the right heart, thereby reducing the risk of suddencardiac failure during shunt creation.

FIG. 5A illustrates a diagrammatical representation of an SMA coil 500for creating a septal defect, in accordance with an embodiment of thepresent specification. FIG. 5B is another view of the SMA coil 500 forcreating a septal defect shown in FIG. 5A. FIG. 5C illustrates a crosssectional view of the SMA coil 500 for creating a septal defect shown inFIG. 5A. Referring to FIGS. 5A, 5B and 5C simultaneously, coil 500comprises two inner loops 502 threaded with magnets 504 interspersedwith spacers 506 and two outer loops 508 and 510 having diameters largerthan diameters of the inner loops 502. In an embodiment, diameters ofthe inner loops 502 and the outer loops 508, 510 of the coil 500 areapproximately 16 mm and 24 mm respectively. In an embodiment, a width ofthe coil 500, measured from a proximal end 501 to a distal end 509 ofthe coil 500, is approximately 11.3 mm and a thickness of SMA wireforming the coil 500 is approximately 0.6 mm. In an embodiment, adiameter of the magnets 504 and a diameter of the spacers 506 areapproximately 2.5 mm. In various embodiments, the spacers 306 comprisesilicone or Nitinol tubes or O-rings or circular balls. One of the outerloops 508 is placed at a proximal end of a wall of a first organ ortissue portion and the other outer loop 510 is placed at a distal endbeyond a wall of a second organ or tissue portion.

FIG. 6A illustrates a catheter 602 carrying a needle 604 being deployedin a human heart 608 for creating a puncture or hole 605 in a wall oratrial septum 610 between the left and right atriums 612, 606 of theheart 608, in accordance with an embodiment of the presentspecification. FIG. 6B illustrates an SMA coil device 614 comprisingmagnets deployed within the left and right atriums 612, 606 through thepuncture 605 created in the wall 610 for causing a septal defect in thewall 610, in accordance with an embodiment of the present specification.Referring to FIG. 6A, a trans-septal catheter 602 carrying a needle 604is advanced through an inferior vena cava 603 and delivered within aright atrium 606 of a heart 608 via an endoscope (not shown). The needle604 is used to puncture the wall/atrial septum 610 between the rightatrium 606 and the left atrium 612. The needle 604 is then removed andan endoscope or catheter, carrying the SMA coil device 614 in asubstantially linear pre-deployment configuration, is advanced throughthe puncture 605 such that its distal end is positioned in the leftatrium 612. Optionally, in other embodiments, the SMA wire in the device614 is adapted to make the puncture. The device 614 is delivered, in asubstantially linear pre-deployment configuration, via the catheterthrough the puncture 605 in the atrial septum 610. As the device 614 isextended beyond the distal end of the catheter, exposure to bodytemperature causes the device to begin coiling into its post-deploymentcoiled configuration. Once the outer loops at the distal end 618 of thedevice have been deployed, the catheter is retracted to position itsdistal end in the puncture. The inner loops are then deployed at thepuncture 605 position. The endoscope or catheter is then furtherretracted to position its distal end in the right atrium 606. Theremainder of the device 614 is then deployed such that the outer loopsat the proximal end deploy within the right atrium 606. As shown in FIG.6B, SMA coil device 614 comprising magnets 616 threaded on inner loops(as shown in FIGS. 5A, 5B and 5C) has been deployed in the heart 608 viaan endoscope or catheter (not shown), with a distal end 618 pushed in tothe left atrium 612 via the puncture 605 made in the septum 610. In afully deployed position, a proximal end 620 of the coil device 614remains in the right atrium 606 while the distal end 618 is positionedin the left atrium 612. The inner loops of coil device 614 hold thetissue of the septum 610 between them and the attraction between themagnets threaded on the inner loops further increases the compressiveforce exerted by the coil device 614 on the tissue, eventually causing adesired septal defect between the left and the right atriums of theheart.

FIG. 7 is a flowchart illustrating the steps of using a coiled SMA wirefor creating a septal defect in a human heart, in accordance with anembodiment of the present specification. At step 702, in order to form aseptal defect or shunt between a first chamber and a second chamber of aheart, firstly, a wall/septum between the two chambers is identified. Atstep 704, the septum between the identified chambers is pierced by usinga needle encased in a catheter positioned in the right heart chamber toobtain a trans-septal puncture. At step 706, a coiled SMA wire havingmagnets threaded on adjacent inner loops (such as shown in FIG. 5A),wherein the diameter of outer loops is greater than that of inner loops,is deployed through the trans-septal puncture, such that approximatelyhalf of the coil is in the first chamber and approximately the otherhalf is in the second chamber. During deployment, at step 708, the SMAwire changes from a substantially linear pre-deployment shape to acoiled post-deployment shape. At step 710, the inner loops of the coilcompress due to the attractive forces between the magnets, causingpressure necrosis, and slowly cut through the septum forming a septaldefect between the first and the second chambers of the heart. At step712, the large diameter outer coil loops without the magnets anchor thecoil in the septal defect preventing the coil from passing spontaneouslyor dislodging.

FIG. 8A illustrates a human heart 800 comprising a healthy mitral valve802. FIG. 8B illustrates a human heart 801 suffering from a mitral valve803 incompetence or a mitral prolapse condition. Referring to FIG. 8A,mitral valve 802 is located between left atrium 804 and left ventricle806. The mitral valve 802 opens due to increased pressure as the leftatrium 804 fills with blood, and allows blood to flow through into theleft ventricle 806 as the heart expands (diastole).

As the heart contracts (systole), the mitral valve 802 closes, therebyforcing blood 807 to flow into aorta 808. This process is vital to theheart's function. Mitral valve prolapse or incompetence occurs when themitral valve does not close properly during systole. This may causeblood to leak the wrong way back into the left atrium, known asregurgitation, which leads to shortness of breath, palpitations, andchest pain. Referring to FIG. 8B, due to an incompetence or prolapse ofmitral valve 803, blood 810 flows back into the left atrium 804 causinghealth problems.

FIG. 9A illustrates a closed healthy mitral valve 902 in a human heart900. FIG. 9B illustrates a mitral valve 903 in a prolapse condition in ahuman heart 901. FIG. 9C illustrates a pair of magnets 912, 914 deployedon each leaflet 932, 934 of the prolapsed mitral valve 903 shown in FIG.9B, in accordance with an embodiment of the present specification. FIG.9D illustrates the prolapsed mitral valve 903 of FIG. 9C closedappropriately due to attractive forces between the magnets 912, 914, inaccordance with an embodiment of the present specification. Referring toFIGS. 9A, 9B, 9C and 9D simultaneously, a healthy mitral valve 902 in aclosed state separates a left atrium 904 of the heart from a leftventricle 906. In a prolapsed or incompetence condition, a prolapsedmitral valve 903 does not close properly, allowing blood 908 from theleft ventricle 906 to regurgitate back into the left atrium 904 as theleft ventricle 906 contracts. In an embodiment, as shown in FIG. 9C, apair of magnets 912 and 914 are deployed on a left and right leaflet932, 934 respectively of the prolapsed mitral valve 903. As theprolapsed mitral valve 903 begins to close, the attraction between themagnets 912, 914 increases, causing the leaflets 932, 934 of the valve903 to come closer to one another, assisting the mitral valve 903 inclosing substantially or completely and thereby eliminating theprolapsed condition. FIG. 9D illustrates the magnets 912, 914 in closeproximity to one another with the leaflets 932, 933 in contact with eachother and the mitral valve 903 closed. In various embodiments, themagnets 912, 914 comprises a single magnet, a plurality of magnets, oran SMA wire with magnets threaded thereon, as described in detail inFIGS. 10A through 11B. During forward flow, the pressure from flow onthe leaflets 932, 933 separates the magnets 912, 914 and, as thedistance between magnets 912, 914 increases, the attraction forceexponentially decreases, allowing the valve to open for forward flow.Therefore, the valve defect device does not produce any significantimpairment of valvular function during forward flow, but ratherpreferentially reduces reverse or back flow through valve 903.

In an embodiment, a magnet coupled with a proximal end of astraight/linear SMA wire is delivered to each leaflet of a prolapsedmitral valve. A distal end of the SMA wire comprises a sharp end forpuncturing into the mitral valve leaflet. After piercing, due to bodyheat, the straight/linear SMA wire coils up, i.e. changes shape to anon-linear configuration, thereby anchoring the magnet to the leaflet.FIG. 10A illustrates an SMA coil with at least one magnet beingdelivered to a mitral valve leaflet, in accordance with an embodiment ofthe present specification. A catheter 1002 is advanced through aninferior vena cava 1001 and used to puncture a septum of a heart 1004and deliver an SMA wire coupled at a proximal end to a magnet toleaflets of a mitral valve 1006. FIG. 10B illustrates leaflets 1005,1007 of the mitral valve 1006 closed due to attraction between themagnets of SMA wire and magnet devices 1008, 1010, in accordance with anembodiment of the present specification. FIG. 10C illustrates an SMAwire 1012 coupled with a magnet 1010, in accordance with an embodimentof the present specification. Magnet 1010 is coupled with a proximal endof the SMA wire 1012. Distal end of the SMA wire 1012 comprises a sharppoint 1014 for piercing a mitral valve leaflet for anchoring the magnet1010 therein. In some embodiments, magnet 1010 includes a threadedopening at its proximal end for coupling with a delivery device asdescribed with reference to FIG. 13. In other embodiments, the SMA wire1012 includes a separate connecting component at its proximal end forcoupling with the delivery device depicted in FIG. 13. FIGS. 10D, 10E,and 10F illustrate random post-deployment configurations 1016, helicalpost-deployment configurations 1018, and spiral configurations 1020respectively, of an SMA wire upon being delivered at a deployment site,in accordance with embodiments of the present specification.

In embodiments, magnets threaded in SMA wires may be used to treat valvedysfunction in various portions of the heart. FIG. 11A illustrates aheart 1100 depicting a myocardium 1101 and fibrous skeleton 1103 andshowing a plurality of heart valves closed by using magnets threaded inSMA wires. As shown in FIG. 11A, valve dysfunctions in mitral valve1102, tricuspid valve 1104, aortic valve 1106, pulmonary valve 1108 mayall be treated by using devices comprising magnets threaded on an SMAwire 1112, 1114, 1116, 1118 respectively, deployed at the valve site.

FIG. 11B illustrates a portion of an SMA wire/magnet device, comprisinga magnet threaded on an SMA wire, deployed at a valve site, inaccordance with an embodiment of the present specification. Magnet 1120is threaded on a first portion of SMA wire 1122, which pierces a valveleaflet 1124 such that the magnet 1120 rests on one side of the leaflet1124 and a second portion of the SMA wire 1126, coiled due to body heat,rests on a second side of the leaflet 1124. Referring to FIGS. 9Cthrough 11B, as the valve starts to close, the magnets come closer andthe attraction force between them increases exponentially, closing thevalve. As the valve starts to open, the distance between the magnetsincreases and the attraction forces between them decrease exponentially,allowing the valve to open easily.

FIG. 12 illustrates a graph showing the exponential relationship betweenthe distance and magnetic force between magnets, in accordance with anembodiment of the present specification. Curve 1200 represents themagnetic field strength which decreases exponentially with increasingdistance, as shown in FIG. 12. Referring to FIG. 10B, as the valveleaflets 1005, 1007 come together, the magnetic strength between the twomagnets of the two SMA wire and magnet devices 1008, 1010 increasesexponentially, keeping the valve 1006 shut and preventing regurgitation.When the forward blood flow opens the valve 1006, the magnetic forcebetween the two magnets 1008, 1010 decreases exponentially and the valveleaflets, open allowing for forward blood flow.

FIG. 13 illustrates a magnet 1306 threaded on an SMA wire 1302 to bedeployed within a body via a push catheter 1308, in accordance with anembodiment of the present specification. A linear SMA wire 1302 isthreaded through an orifice 1304 of a cylindrical shaped magnet 1306.

During deployment within a body, a pusher catheter 1308 is coupled witha proximal end 1310 of an SMA wire and magnet device. In an embodiment,the pusher 1308 includes a threaded distal end 1309 for coupling withthe proximal end 1310 of the SMA wire and magnet device. In embodiments,the proximal end of the SMA wire and magnet device includes a threadedopening for receiving and coupling with the threaded distal end 1309 ofthe SMA wire and magnet device. Once the SMA wire and magnet device isdelivered, the pusher 1308 is disengaged from the device by rotating thepusher 1308 in a counter clockwise direction to remove the distal end1309 of the pusher from the proximal end of the SMA wire and magnetdevice. In one embodiment, the most proximate magnet 1306 couples withthe pusher 1308 and includes a threaded opening at its proximal end forengaging with the distal end of the pusher 1308. In other embodiments,the SMA wire and magnet device includes a separate connecting componentat its proximal end for coupling with the pusher 1308. In an embodiment,a diameter of the cylindrical magnet 1306 is approximately 2.5 mm, and adiameter of the orifice 1304 is approximately 0.9 mm. In an embodiment,a length of the cylindrical magnet 1306 is approximately 2.5 mm. Invarious embodiments, the delivery device comprising a pusher catheter1308 of FIG. 13 can be used to deploy either the shunt creating devicesdisclosed in the present specification (for example, depicted withreference to FIGS. 3A-6B and 14A-16B) or the valve defect devicesdisclosed in the present specification (for example, with reference toFIGS. 8A-11B).

FIGS. 14A, B, C, and D illustrate another example of a Shape MemoryAlloy (SMA) coil and magnet device 1400 that may be used to create aseptal defect, in accordance with embodiments of the presentspecification. FIG. 14A is a side view of the SMA coil and magnet device1400. FIG. 14B is a cross-sectional view of the SMA coil and magnetdevice 1400 of FIG. 14A. FIG. 14C is a top-down view of the SMA coil andmagnet device 1400 of FIG. 14A. FIG. 14D is a perspective view of theSMA coil and magnet device 1400 of FIG. 14A. Referring together to FIGS.14A, B, C, and D, coil 1400 comprises two inner loops 1402. Inner loops1402 are threaded with magnets 1404 interspersed with spacers 1406. Thetwo ends of the inner loops 1402 are extended to two corresponding outerloops 1408 and 1410. In an embodiment, outer loop 1408 is positioned ata proximal end of a wall of a first organ or tissue portion, and may bereferred to as proximal outer loop 1408. In an embodiment, outer loop1410 is positioned at a distal end beyond a wall of a second organ ortissue portion, and may be referred to as distal outer loop 1410. Inembodiments, outer loops 1408 and 1410 have a diameter that is greaterthan a diameter of inner loops 1402. In an embodiment, the outer loopshave a diameter of 34 mm and the inner loops have a diameter of 18.5 mmwhen measured from an outer surface of the magnets on the inner loopsand 16 mm when measured from the SMA wire of the inner loops. In anembodiment, a width of coil 1400 is approximately 7.3 mm and a thicknessof the SMA wire 1401 of the device 1400 is approximately 0.6 mm. In anembodiment, a diameter of the magnets 1404 is approximately 2.5 mm. Invarious embodiments, spacers 1406 comprise silicone or Nitinol tubes orO-rings or circular balls. In some embodiments, in order to assist withproper placement, the spacers 1406 are colored differently depending onwhich side of the created septal defect they will be deployed. In anembodiment, referring to FIG. 14A, spacers 1406 p are configured to bepositioned on a proximal side of the septal defect and are a firstcolor, for example, red, while spacers 1406 d are configured to bepositioned on a distal side of the septal defect and are a second color,for example, black.

In embodiments of the present specification, outer loops 1408 and 1410are comprised of a non-linear wire. In one embodiment, outer loops 1408and 1410 are comprised of a wire that is structured like a wave, forexample a sine wave, such that the troughs of the wave are positionednear the inner loops 1402, and have an approximate diameter of 18.5 mm,and the crests of the wave are positioned away from the inner loops. Thewave structure enhances anchoring function by providing more points ofcontact of the wire with the body tissue than a simple loop.Accordingly, it is preferred for each outer loop to have a varyingradius, thereby forming a circle with a wave-like perimeter. In anembodiment, diameter of the loop measured at the crests of outer loops1408 and 1410 is 34 mm. In an embodiment, the angle formed betweenconsecutive crests of each loop is 60°, resulting in 6 crests (nodes) ineach outer loop 1408 and 1410. In an alternative embodiment, the anglebetween consecutive crests is 90°, providing 4 crests in each outer loop1408 and 1410. In another alternative embodiment, the angle betweenconsecutive crests is 120°, providing 3 crests in each outer loop 1408and 1410. In embodiments, the angle between consecutive crests may rangefrom 15° to 180°.

In embodiments, each outer loop 1408 and 1410 is positioned such thatthe loops stagger in a manner that each crest of outer loop 1408corresponds to each trough of outer loop 1410, and vice-versa, whenviewed from the top (see FIG. 14C). This configuration allows forgreater stability by staggering the contact points of the outer loops oneach side of the tissue (for example, atrial septum), distributing thepressure applied by the coil to the body tissue move evenly to supportthe device in place. In addition, staggering the nodes prevents pinchingof the tissue at the same point from both sides, which couldinadvertently lead to tissue necrosis, resulting in unwanted increase inthe size of the shunt and passage of the device.

In embodiments, tip of proximal outer loop 1408 includes a crimped probe1412. Additionally, tip of distal outer loop 1410 includes a weldedcautery probe 1414. Crimped probe 1412 may include a screw (threadedend) to ease connection with a delivery device and deployment at theproximal end of the wall of the first organ or tissue portion. In anembodiment, a diameter of the screw head of crimped probe 1412 isapproximately 1.5 mm, whereas the diameter of the crimped tip of thescrew within crimped probe 1412 is approximately 1.3 mm. Cautery tip1414 may enable puncture at the distal end through the wall of the firstorgan or tissue portion (for example, atrial septum). In an embodiment,the tip of cautery probe 1414 has a diameter of approximately 2.67 mm.

FIGS. 15A, B, C, and D illustrate another example of a Shape MemoryAlloy (SMA) coil and magnet device 1500 that includes at least two wiresbraided together, which may be used to create a septal defect, inaccordance with embodiments of the present specification. FIG. 15A is aside view of the SMA coil and magnet device 1500. FIG. 15B is across-sectional view of the SMA coil and magnet device 1500 of FIG. 15A.FIG. 15C is a top-down view of the braided SMA coil and magnet device1500 of FIG. 15A. FIG. 15D is a perspective view of the braided SMA coiland magnet device 1500 of FIG. 15A. Referring together to FIGS. 15A, B,C, and D, coil 1500 comprises two inner loops 1502. Inner loops 1502 arethreaded with magnets 1504 interspersed with spacers 1506. The two endsof the inner loops 1502 are extended to two corresponding outer loops1508 and 1510. In an embodiment, outer loop 1508 is positioned at aproximal end of a wall of a first organ or tissue portion, and may bereferred to as proximal outer loop 1508. In an embodiment, outer loop1510 is positioned at a distal end beyond a wall of a second organ ortissue portion (for example, atrial septum), and may be referred to asdistal outer loop 1510. In embodiments, outer loops 1508 and 1510 have adiameter that is greater than a diameter of inner loops 1502. In anembodiment, the outer loops have a diameter of 34 mm, and the innerloops have a diameter of 18.5 mm when measured from an outer surface ofthe magnets on the inner loops and 16 mm when measured from the SMA wireof the inner loops. In an embodiment, a width of coil 1500 isapproximately 7.3 mm and a thickness of each SMA wire 1501 of the device1500 is approximately 0.6 mm, for a combined thickness of adjacentbraided wires of approximately 1.2 mm. In an embodiment, a diameter ofthe magnets 1504 is approximately 2.5 mm. In various embodiments,spacers 1506 comprise silicone or Nitinol tubes or O-rings or circularballs.

In embodiments of the present specification, outer loops 1508 and 1510are comprised of a non-linear combined wire 1516. In embodiments, thedevice 1500 includes a combined wire 1516 which comprises at least twowires 1501 that are combined with each other, such as by braiding. Theadditional wire(s) provides added support to outer loops 1508 and 1510,thereby making them stronger. Providing additional wires increases thestrength of the outer coil without causing too much strain in the wire.Increasing the thickness or diameter of the wire would result in ahigher strain when changing the wire from a loop shape to a straightshape. To accommodate a thicker wire, the diameter of the loop wouldneed to be increased. By using two wires, the strength of the coil isincreased without needing to increase the diameter of the loop. In oneembodiment, outer loops 1508 and 1510 are comprised of braided wire 1516that is structured like a wave, for example a sine wave, such that thetroughs of the wave are positioned near the inner loops 1502, and havean approximate diameter of 18.5 mm, and the crests of the wave arepositioned away from the inner loops. In an embodiment, diameter of theloop measured at the crests of outer loops 1508 and 1510 is 34 mm. In anembodiment, the angle formed between consecutive crests of each loop is60°, resulting in 6 crests (nodes) in each outer loop 1508 and 1510. Inan alternative embodiment, the angle between consecutive crests is 90°,providing 4 crests in each outer loop 1508 and 1510. In anotheralternative embodiment, the angle between consecutive crests is 120°,providing 3 crests in each outer loop 1508 and 1510. In embodiments, theangle between consecutive crests may range from 15° to 180°.

In embodiments, each outer loop 1508 and 1510 is positioned such thatthe loops stagger in a manner that each crest of outer loop 1508correspond to each trough of outer loop 1510, and vice-versa, whenviewed from the top (see FIG. 15C). As noted above, this configurationallows for greater stability by staggering the contact points of theouter loops on each side of the tissue (for example, atrial septum) tosupport the device in place. In addition, staggering the nodes preventspinching of the tissue at the same point from both sides, which couldinadvertently lead to tissue necrosis, resulting in unwanted increase inthe size of the shunt and passage of the device.

In embodiments, tip of proximal outer loop 1508 includes a crimped probe1512. Additionally, tip of distal outer loop 1510 includes a weldedcautery probe 1514. Crimped probe 1512 may include a screw (threadedend) to ease connection with a delivery device and deployment at theproximal end of the wall of the first organ or tissue portion. In anembodiment, a diameter of the screw head of crimped probe 1512 isapproximately 1.5 mm, whereas the diameter of the crimped tip of thescrew within crimped probe 1512 is approximately 1.3 mm. Cautery tip1514 may enable puncture at the distal end through the wall of thesecond organ or tissue portion (for example, atrial septum). In anembodiment the tip of cautery probe 1514 has a diameter of approximately2.67 mm.

FIGS. 16A and B illustrate another example of a Shape Memory Alloy (SMA)coil and magnet device 1600 that includes cautery probes and screws atboth tips of outer loops 1608 and 1610, which may be used to create aseptal defect, in accordance with embodiments of the presentspecification. FIG. 16A is a top-down view of the SMA coil and magnetdevice 1600. FIG. 16B is a perspective view of the SMA coil and magnetdevice 1600 of FIG. 16A. Referring together to FIGS. 16A and B, coil1600 comprises two inner loops 1602. Inner loops 1602 are threaded withmagnets 1604 interspersed with spacers 1606. The two ends of the innerloops 1602 are extended to two corresponding outer loops 1608 and 1610.In an embodiment, outer loop 1608 is positioned at a proximal end of awall of a first organ or tissue portion, and may be referred to asproximal outer loop 1608. In an embodiment, outer loop 1610 ispositioned at a distal end beyond a wall of a second organ or tissueportion (for example, atrial septum), and may be referred to as distalouter loop 1610. In embodiments, outer loops 1608 and 1610 have adiameter that is greater than a diameter of inner loops 1602. In anembodiment, the outer loops have a diameter of 34 mm, and the innerloops have a diameter of 18.5 mm when measured from an outer surface ofthe magnets on the inner loops and 16 mm when measured from the SMA wireof the inner loops. In an embodiment, a width of coil 1600 isapproximately 7.3 mm and a thickness of the SMA wire 1601 of the device1600 is approximately 0.6 mm. In an alternative embodiment, coil 1600includes at least two wires braided together, in which case a thicknessof the SMA wires braided together and forming outer loops 1608 and 1610of coil 1600 is approximately 1.2 mm. In an embodiment, a diameter ofthe magnets 1604 is approximately 2.5 mm. In various embodiments,spacers 1606 comprise silicone or Nitinol tubes or O-rings or circularballs.

In embodiments of the present specification, outer loops 1608 and 1610are comprised of a non-linear wire. In one embodiment, outer loops 1608and 1610 are comprised of a wire that is structured like a wave, forexample a sine wave, such that the troughs of the wave are positionednear the inner loops 1602, and have an approximate diameter of 18.5 mm,and the crests of the wave are positioned away from the inner loops. Inan embodiment, diameter of the loop measured at the crests of outerloops 1608 and 1610 is 34 mm. In an embodiment, the angle formed betweenconsecutive crests of each loop is 60°, resulting in 6 crests (nodes) ineach outer loop 1608 and 1610. In an alternative embodiment, the anglebetween consecutive crests is 90°, providing 4 crests in each outer loop1608 and 1610. In another alternative embodiment, the angle betweenconsecutive crests is 120°, providing 3 crests in each outer loop 1608and 1610. In embodiments, the angle between consecutive crests may rangefrom 15° to 180°.

In embodiments, each outer loop 1608 and 1610 is positioned such thatthe loops stagger in a manner that each crest of outer loop 1608correspond to each trough of outer loop 1610, and vice-versa, whenviewed from the top (see FIG. 16A). As noted above, this configurationallows for greater stability by staggering the contact points of theouter loops on each side of the tissue (for example, atrial septum) tosupport the device in place. In addition, staggering the nodes preventspinching of the tissue at the same point from both sides, which couldinadvertently lead to tissue necrosis, resulting in unwanted increase inthe size of the shunt and passage of the device.

In embodiments, tips of proximal and distal outer loops 1608 and 1610each include a screw 1612 encompassed in a magnet 1618. Additionally,tip of screws 1612 are connected to cautery probes 1614. Screws 1612 mayease deployment at the proximal end of the wall of the first organ ortissue portion as well as at the distal end beyond the wall of thesecond organ or tissue portion. Cautery probes 1614 may ease puncture ofthe corresponding locations for deployment.

Screw 1612 may be partially or wholly encompassed in a first magnet1618. Screw 1612 may ease connection with a delivery device anddeployment at the proximal end of the wall of the first organ or tissueportion. Cautery tip 1614 may also be partially encompassed in a secondmagnet 1618. Cautery tip 1614 may enable puncture at the distal endbeyond the wall of the second organ or tissue portion. In embodiments,encompassing magnets 1618 align with and attach themselves to magnets1604 in the inner loops 1602 of coil 1600. The attaching mechanism ofthe magnets enables locking of the wire of outer loops 1608 and 1610back to coil 1600.

The above examples are merely illustrative of the many applications ofthe system of present specification. Although only a few embodiments ofthe present invention have been described herein, it should beunderstood that the present invention might be embodied in many otherspecific forms without departing from the spirit or scope of theinvention. Therefore, the present examples and embodiments are to beconsidered as illustrative and not restrictive, and the invention may bemodified within the scope of the appended claims.

What is claimed is:
 1. A shunt device for creating a shunt in an atrialseptum of a patient, comprising: a wire comprised of a shape memoryalloy, wherein the wire is adapted to transform from a substantiallystraight wire to a coil shape upon heating and wherein the wire, upontransforming to the coil shape, comprises at least two inner loops andat least two outer loops, wherein a diameter of the at least two innerloops are each less than a diameter of each of the at least two outerloops, and wherein the wire, when in the coil shape, is adapted to exerta compressive force upon layers of tissue caught between the at leasttwo inner loops; and a plurality of magnets coupled to the at least twoinner loops, wherein the plurality of magnets are adapted to provide acompressive force to adjacent inner loops of the wire in the coil shape,thereby further causing the wire to cut through the layers of tissue andcreate a shunt of a diameter less than the diameter of the outer loopssuch that the at least two outer loops do not pass through said shunt.2. The shunt device of claim 1, wherein at least one end of the wirecomprises a connection means for connecting with a delivery device. 3.The shunt device of claim 2 wherein the connection means comprises a nutand a screw.
 4. The shunt device of claim 1 wherein a diameter of thewire when in a coil shape ranges between
 0. 1 mm to 10 mm and a lengthof the wire ranges from 1 cm to 250 cm.
 5. The shunt device of claim 1wherein the wire comprises Nitinol.
 6. The shunt device of claim 1wherein the plurality of magnets are positioned on the at least twoinner loops such that repulsive forces between adjacent magnets of theplurality of magnets on a same one of the at least two inner loops causesaid adjacent magnets to maintain a predefined distance between them. 7.The shunt device of claim 1 wherein the plurality of magnets are rareearth magnets covered with at least one of gold, nickel or titanium. 8.The shunt device of claim 1 wherein the wire, when in a coiled shape,has a maximum cross sectional diameter ranging from 5 mm to 50 mm. 9.The shunt device of claim 1 wherein each of the plurality of magnetshave a maximum cross sectional length ranging from 0.2 mm to 7 mm and apull force ranging from 0.1 lb. to 4 lb.
 10. The shunt device of claim 1wherein a pull force between any two consecutively placed magnets of theplurality of magnets is approximately 2.318 N.
 11. The shunt device ofclaim 1 wherein a length, an inner diameter and an outer diameter ofeach of the plurality of magnets is 3 mm, 0.66 mm and 2.5 mmrespectively.
 12. The shunt device of claim 1 wherein a shape of theshunt formed by using the shunt device is determined by a shape of theat least two inner loops.
 13. The shunt device of claim 6 wherein atleast 50% of the adjacent magnets on each loop are arranged with likepoles facing each other.
 14. The shunt device of claim 1 whereinadjacent magnets on each of the at least two inner loops are separatedby a non-ferromagnetic spacer, thereby preventing adjacent magnets fromattaching to each other.
 15. The shunt device of claim 1 wherein each ofthe at least two outer loops are connected to opposing ends of the atleast two inner loops.
 16. The shunt device of claim 1 wherein twoopposing tips of the wire correspond to ends of the at least two outerloops and comprise a crimped probe at one of the two opposing tips and acautery probe at a second of the two opposing tips.
 17. The shunt deviceof claim 16 wherein the crimped probe is attached to a screw as aconnection means for connecting the wire with a delivery device.
 18. Theshunt device of claim 16 wherein a magnet of the plurality of magnets atleast partially encompasses the cautery probe.
 19. The shunt device ofclaim 17 wherein a magnet of the plurality of magnets at least partiallyencompasses the screw.
 20. The shunt device of claim 17 wherein thedelivery device comprises a mechanism for heating the shunt device priorto deploying in the body of the patient.